IO2 



THE SUPERIOR EXTREMITY 



and the ulnar arteries. In the proximal part of the arm it lies 

 to the medial side of the humerus, but as it approaches the 

 elbow it passes to the front of the humerus. 



This change of position must be borne in mind when 

 pressure is applied to the vessel with the view of controlling 

 the flow of blood through it. In the proximal part of the arm 

 the pressure must be directed laterally and backwards, and in 

 the distal part directly backwards. 



Brachial 

 artery 



Median nerve 



Medial 

 cutaneous 

 nerve of the - 

 forearm 



Basilic vein . 

 Medial inter- ; 

 muscular, 4^ 

 septum 

 Ulnar ' 

 nerve 



, Cephalic vein 



Musculo-cutaneous nerve 



Profunda artery 

 r of the arm 



- -Radial nerve 



~-L^_. Brachio-radialis 

 muscle 



-',_ Lateral intermuscular 

 septum 



FIG. 42. Transverse section through the Distal Third of the 

 Right Arm. 



Relations. The brachial artery is superficial in the 

 whole of its length. To expose it, therefore, it is necessary 

 to reflect only the skin and the fascia ; but it is overlapped, 

 from the lateral side, by the medial margins of the coraco- 

 brachialis and biceps brachii (see Figs. 10, 41). At the bend 

 of the elbow it is crossed superficially by the lacertus fibrosus, 

 which intervenes between it and the median cubital vein. 



The basilic vein lies to the medial side of the artery and 

 on a somewhat posterior plane. In the distal part of the 

 arm it is separated from the artery by the deep fascia ; but 

 in the proximal part, after the vein has pierced the fascia, 

 it comes into closer relationship with the artery. The two 

 vense comites are closely applied to the sides of the artery, 



